Metal–ligand Lability and Ligand Mobility Enables Framework Transformation via Ligand Release in a Family of Crystalline 2D Coordination Polymers

A family of seven silver(I)‐perfluorocarboxylate‐quinoxaline coordination polymers, [Ag(4)(O(2)CR(F))(4)(quin)(4)] 1–5 (R(F)=(CF(2))(n‐1)CF(3))(4), n=1 to 5); [Ag(4)(O(2)C(CF(2))(2)CO(2))(2)(quin)(4)] 6; [Ag(4)(O(2)CC(6)F(5))(4)(quin)(4)] 7 (quin=quinoxaline), denoted by composition as 4 : 4 : 4 phases, was synthesised from reaction of the corresponding silver(I) perfluorocarboxylate with excess quinoxaline. Compounds 1–7 adopt a common 2D layered structure in which 1D silver‐perfluorcarboxylate chains are crosslinked by ditopic quinoxaline ligands. Solid‐state reaction upon heating, involving loss of one equivalent of quinoxaline, yielding new crystalline 4 : 4 : 3 phases [Ag(4)(O(2)C(CF(2))(n‐1)CF(3))(4)(quin)(3)](n) (8–10, n=1 to 3), was followed in situ by PXRD and TGA studies. Crystal structures were confirmed by direct syntheses and structure determination. The solid‐state reaction converting 4 : 4 : 4 to 4 : 4 : 3 phase materials involves cleavage and formation of Ag−N and Ag−O bonds to enable the structural rearrangement. One of the 4 : 4 : 3 phase coordination polymers (10) shows the remarkably high dielectric constant in the low electric field frequency range.